在实体查询的强类型LINQ中填充列表

Question

我是LINQ新手，我只是想在LINQ to Entities查询中填充一个List。 任何帮助将不胜感激。

类“ SearchCriteria”如下所示：

public class SearchCriteria
{
   public IList<DTOEventType1> eventTypes { get; set; }
   public IList<DTOLocation1> locs { get; set; }
   [DataType(DataType.Date)]
   [DisplayFormat(ApplyFormatInEditMode = true,
      DataFormatString="0:dd/MM/yyyy}")]
   public DateTime? searchDate { get; set; }
   public List<PortfolioLibraryMVC4V2.Domain.DTO.DTOCalendarEvents> 
      CalendarEvents;
}

我的查询如下所示：

var query = from E in medRepo.evt
    join L in medRepo.loc on E.LocationID equals L.LocationID
    join ET in medRepo.evtType on E.EventTypeID equals    
               ET.EventTypeID 
    where IDsOfSelectedEventTypes.Contains(E.EventTypeID) &&
          IDsOfSelectedLocations.Contains(L.LocationID) && 
          E.EventStart > eventslocs.searchDate 

    select new SearchCriteria
    {
        CalendarEvents = query.Select(x => new DTOCalendarEvents
        {
            Name = ET.Name,
            EventStart = E.EventStart,
            EventEnd = E.EventEnd
            }).ToList()
        };

        var datalist = query.ToList();

我正在尝试在上述查询的select中填充Class SearchCriteria中的列表“ CalendarEvents”。 当前，我收到错误消息“在声明之前尝试使用局部变量查询”，因此显然我的语法不正确。 有人可以告诉我正确的方法吗？

谢谢，

皮特

Answer 1

您可以在linq查询之外使用SearchCriteria 。

var searchCriteria = new SearchCriteria();

searchCriteria.CalendarEvents = (from E in medRepo.evt
                                 join L in medRepo.loc 
                                 on E.LocationID equals L.LocationID
                                 join ET in medRepo.evtType 
                                 on E.EventTypeID equals ET.EventTypeID 
                                 where                     
                                 IDsOfSelectedEventTypes.Contains(E.EventTypeID) 
                                 && IDsOfSelectedLocations.Contains(L.LocationID) 
                                 && E.EventStart > eventslocs.searchDate)
                                .Select(x => new DTOCalendarEvents
                                {
                                 Name = ET.Name,
                                 EventStart = E.EventStart,
                                 EventEnd = E.EventEnd
                                })
                               .ToList();

基本上，我们只需要LINQ查询中的事件列表。

Answer 2

试试看：

var query = from E in medRepo.evt
    join L in medRepo.loc on E.LocationID equals L.LocationID
    join ET in medRepo.evtType on E.EventTypeID equals    
               ET.EventTypeID 
    where IDsOfSelectedEventTypes.Contains(E.EventTypeID) &&
          IDsOfSelectedLocations.Contains(L.LocationID) && 
          E.EventStart > eventslocs.searchDate 
    select new DTOCalendarEvents
    {
            Name = ET.Name,
            EventStart = E.EventStart,
            EventEnd = E.EventEnd
    };

    var datalist = query.ToList();

var searchCriteria = new SearchCriteria();
searchCriteria.CalendarOfEvents = datalist;